210 WISCONSIN PHYTOPLANKTON 



PLATE 83. 

 All figures x500. 



Page 



Figs. 1-3. Staurastrum furcatum (Ehr.) De Br6b 118 



Figs. 4-7. Staurastrum furcigerum De Br6b 122 



Figs. 8-11. Staurastrum furcigerum var. armigerum forma gracillimum .... 123 



Figs. 12-14. Staurastrum leptacanthum Nordst 123 



Fig. 15. Staurastrum Arctiscon var. glalrum W. & G. S. West 125 



